Permafrost.
Permafrost, areas of permanently frozen ground, covers large areas of the planet at higher latitudes and elevations. The earth's temperature is rising more rapidly at higher latitudes than the average temperature rise, leading to large areas of permafrost starting to melt. In Alaska and Siberia this melting is having devastating consequences. Infrastructure built on the permafrost like roads and houses are starting to buckle and sink. Huge swathes of Black Spruce forest are suffering from the phenomenon known as drunken forest, where they lean at alarming angles as the ground beneath them melts and subsides. Summer lakes that formed on top of the permafrost are starting to disappear as the frozen barrier melts and the water drains away.